From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1FC50C04AB6 for ; Tue, 28 May 2019 12:48:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC99920883 for ; Tue, 28 May 2019 12:48:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="FBhhhi+Z" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727505AbfE1MsA (ORCPT ); Tue, 28 May 2019 08:48:00 -0400 Received: from mail-pl1-f196.google.com ([209.85.214.196]:33513 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726973AbfE1Mr7 (ORCPT ); Tue, 28 May 2019 08:47:59 -0400 Received: by mail-pl1-f196.google.com with SMTP id g21so8325766plq.0 for ; Tue, 28 May 2019 05:47:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=4OteA4keojZHK2MF5haDWUxtIJtUSMxeYouchlVp2qA=; b=FBhhhi+Z4o39uwPH4T/Ze7TApUywTvM7Rv2kYb3S4S76TdPe0++tkj8dPNo52Rn0BN F3hz7ycsZgYHKnwd+zEz1TlChKc0yPoQYev+klwjWKFa9owxmmVbeyiLZPbPS4TKYZlJ znEimldEL+ulVM3IY1sQMJgusDFEQeqNaon6GmPJTfK6UJMmxfW6VWvShDPtOXqkQ6wP ++4cE38J97CLzTdae4HcrRMWI5l9/LYw9P5LZA5vYj/DAXUvFx8zfZDG/0eJNtTKhKkN ME5JHqUP64KVldcEM0wXDRTTNp0v/1t34HN5g63gFQNAxdwSq4Ef+iSeYoC/9RwNPRi+ 3zFw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=4OteA4keojZHK2MF5haDWUxtIJtUSMxeYouchlVp2qA=; b=ttaJmNx3SIa20UlqP15pe3uaVk0gXdF54YLbDMsfIhXbyP1J42qFbUA7Oc68argxZa a2eLFVX2jywmENsRmxP9Sq9wTvjA0j/pFwjhTCj8MdBTyZZ8QiqnzK+bFrs8J9trG6zi /teKvdSaNgBNiAjGRlaZgKUnqUJ74lIcymGkqBxLSezugoXEp7DDV9QDJ+Z+BaU32/KW jwsiCbWGD4F7TnsHlTuNHD2ZKWp+HrHG6dEomstZr7OIco5ssHjklocJ7zKEHaA+MzDV AuvDDmkgzYtLsTvp4z41Mk5AFUP5lRipx40l4ZvAbkFJUzdL0OiMdM5LVqM4hiIdcnQK +nVg== X-Gm-Message-State: APjAAAUVKVQswCZv4PUa6yvL4MIuIUsL4V0RMrkEKzpy0qa858awIqWN aELUciUt86z8/9bGBJRSXtDxRx6h X-Google-Smtp-Source: APXvYqzQoHtrSOA5eVlo3n4Hf+QHuL+7RxhE1FMrtt8j3HSnmYA3BH3eWeWQzU9Z9zozRZuw+2Lzig== X-Received: by 2002:a17:902:ba95:: with SMTP id k21mr2424640pls.159.1559047679326; Tue, 28 May 2019 05:47:59 -0700 (PDT) Received: from zhanggen-UX430UQ ([66.42.35.75]) by smtp.gmail.com with ESMTPSA id q6sm10543151pfg.7.2019.05.28.05.47.56 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 28 May 2019 05:47:58 -0700 (PDT) Date: Tue, 28 May 2019 20:47:48 +0800 From: Gen Zhang To: Greg KH Cc: rafael@kernel.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [Question: devm_kfree] When should devm_kfree() be used? Message-ID: <20190528124748.GA23945@zhanggen-UX430UQ> References: <20190528003257.GA12065@zhanggen-UX430UQ> <20190528064949.GC2428@kroah.com> <20190528071400.GB18498@zhanggen-UX430UQ> <20190528124138.GA3578@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190528124138.GA3578@kroah.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 28, 2019 at 02:41:38PM +0200, Greg KH wrote: > No, you are not leaking any memory if you do not call that function. > Try it and see :) > > The function is there if you just want to "free the memory now!", it's > not necessary if you return an error as when the device is removed the > memory will be freed then (or if probe fails, depending on the code > path.) > > thanks, > > greg k-h Thanks for your patient replies, Greg. I thinks I am getting to know this issue. Thanks Gen